The present invention relates to a method of manufacturing a semiconductor device, in particular to a technique effective when applied to a method of manufacturing a semiconductor device having a pad electrode made of copper (Cu) and a bonding wire made of copper (Cu).
Japanese Unexamined Patent Application Publication No. 2004-31686 discloses a technique that enables bonding of a gold wire onto a copper bonding pad even when there is a thick copper oxide film on a surface of the bonding pad by using an initial ball where tin is attached to a tip of the gold wire. Further, Japanese Unexamined Patent Application Publication No. 2004-31686 describes that a wire composed mainly of copper is used instead of the gold wire.
Japanese Unexamined Patent Application Publication No. 2015-220248 discloses a technique that couples a bonding wire with an electrode pad through a first film 12d by removing a native oxide film formed on a surface of the electrode pad and thereafter forming the first film 12d made of a conductive member (chrome, titanium, tungsten, or the like) and coupling a wire to the first film 12d. Japanese Unexamined Patent Application Publication No. 2015-220248 also describes a bonding wire made of copper and an electrode pad made of copper.